A variety of optical devices have one or more waveguides positioned on base. The waveguides often guide light signals to other optical components such as modulators, switches, demultiplexers, and light sensors. These waveguides often receive the light signals from a second optical device and/or or guide the light signals to the second optical device. Accordingly, the light signals are often transferred between a waveguide on the optical device and a second waveguide on the second optical device.
The mode size for the waveguide on first optical device is often different than mode size of the second optical device. For instance, the mode size of waveguides on planar optical devices is often much smaller than the mode size of the optical fibers with which the planar optical device exchanges light signals. This mismatch of mode sizes is often addressed by adding a taper to the waveguide that exchanges light signals with the second optical device. For instance, the waveguide on a planar optical device can be tapered such that the mode size of a light signal carried in the waveguide expands to the mode size of the optical fiber with which the waveguide will exchange light signals.
Fabrication of a tapered waveguide on an optical device can interfere with fabrication of the other components on the same optical device. The fabrication challenges become even more evident when the taper is two-dimensional. As a result, there is need for a system that permits the exchange of light signals between different optical devices without complicating the fabrication process.